Now, they are taking things a step further. A full-page ad taken out in Dec. 19's New York Times shows signatures from more than 100 public figures, including Arianna Huffington, Lady Gaga, Martha Stewart, MC Hammer, Goldie Hawn, and Ken Burns.

"The time has come for courage," the ad reads. "The Courage to make our schools and workplaces, our shopping malls and movie theaters -- all the places we share every day -- safe from gun violence. The courage to stand up to the NRA -- to put human life ahead of extreme ideology. The courage to ban weapons of mass murder that at anytime, anywhere, can turn America into a killing field."

"We cannot let the latest massacre fade into memory -- another horrible headline followed by indifference and inaction," the ad continues. "We must speak for those whose voices will never be heard again. e must speak truth to those in power -- and insist that now is the time to do what is right instead of pandering before merchants of death."